Kaioh Michiru , also known as Sailor Neptune, first appears in the Sailormoon S series. She was one of the few talented students who was admitted entrance into the exclusive Mugen Gakuen school. When we first see her, she is in Form 4, or grade 10, and an aspiring violinist, always kind, gentle, and a very good listner (especially to Usagi's many problems throughout the series). However, as Sailor Neptune, she is more ruthless. Her existence as an outer senshi in Sailormoon S was to search for the 3 pure heart crystals, which is why she doesn't feel the need to be loyal to Sailor Moon, the princess, as the inner senshi do. Thus, she is willing to sacrifice the lives of anybody, including the inner senshi, her friends, and even herself. Unkown to Sailor Neptune, she, in fact has one of the pure heart crystals, which when revealed, formed the Deep Aqua Mirror talisman.